CAMBRIDGE -- ''Hallelujah, some things never change," Ellis Paul sang softly, closing Thursday's homage to Club Passim at Sanders Theatre.
The song was about his native state of Maine, but he dedicated it to the small Harvard Square basement that has hosted the folk music haven since 1970 and that was also the final home for legendary '60s coffeehouse Club 47. Both legacies were feted in a nearly five-hour concert featuring five decades of Boston folk stars.
Tom Rush, who hosted Club 47's open mike nights in the early '60s, sang fond favorites and MC'd with a droll persona. Of the collapse of New Hampshire's Old Man of the Mountain landmark, he said, ''It's creepy to outlive a geological feature." And he coyly confessed that his classic goodbye song, ''No Regrets," was actually written as a come-on (and it worked).
The Silver Leaf Gospel Singers, together for 60 years, offered a soaring, testifying set, with 83-year-old Deacon Randy Green hopping into the crowd to assemble an eager choir from the front rows.
That set the stage for hot young folk-rocker Sarah Borges, whose urban rockabilly rippled with good muscle and bad intentions. Catie Curtis displayed a gift for making simple kindness seem edgy and chic, her gorgeous falsetto leaps embellishing the simplicity of her vocals.
Self-described ''housewife by trade" Lori McKenna sang bittersweet ballads of hard romance, such as a wincing portrait of a young mother who ''hasn't talked to a single adult all day," standing in her kitchen, shouting to herself, ''Don't you know who I am?"
Legendary sideman Al Kooper delivered elegant funk with his crack Berklee band. He continues to display a winking sense of fun and a primal understanding of the space between the notes, where the groove really lives.
A lesser songwriter than Paul would have died a slow death following all that by himself. But his arrangements are so complete, his lilting melodies so organic, his lyrics so evocative that even his new songs felt like old friends. And everything he sang, from a love song promising both safe harbor and freedom to an ode to the rowdy glory of American music, seemed to thank Club Passim for never caring one whit whether folk was in fashion.
Club Passim presents a free festival on Cambridge Common today at 11 , with Chris Smither, Jim Kweskin, Spider John Koerner, Jake Armerding, the Resophonics, and others.